Medical gas producer employing a



Jan. 16, 1934. J. NOIROT MEDICAL GAS PRODUCER EMPLOYING A HEATED LIQUID Original Filed Jan. 15, 1930 patented Jan. 16, 1934 I PATENT OFFICE MEDICAL GASY PRODUCER EMPLOYING A HEATED LIQUID I Jean Noirot, Paris, France Application January 15, 1930, Serial No. 421,025,

and in France January 24, 1929.

November :4, 1933 Renewed Claims. (o1. 167-3) The present invention relates to a gas-producing apparatus adapted for medical use and chiefly for inhalations, in which the gas or vapor is produced by heating a liquid in a tube in 5 which the level is constantly equilibrated by a column of compressed air.

The following description with reference to the accompanying drawing shows by way of example an embodiment of the invention.

The tube containing the liquid comprises two branches communicating at the lower part, one branch being vertical and the other inclined; the vertical branchl is the shorter, and it is closed at the top; the inclined branch 2, which is longer,

may be closed at the upper end by a cap or plug 3 screwed to the tube. The said cap is pierced with a central conduit 4 which opens at the exterior by a divergent tapered part in which is disposed a member 5 of corresponding form, through Which is an axial conduit 6 communicating with the exterior by a narrow orifice '7 having for instance a diameter of 0.4 mm. The

said member 5 serves as a valve, and it is held in contact with the cap 3 by a spring strip 8 secured by screws 9 to the outer face of the plug.

The entire tube is maintained in a case 10 serving as a support, upon which the tube may be held by a nut 11 secured to the said case. The tube is filled with liquid 12 through its inclined branch 2, in such manner that a column of air will be contained in the vertical branch above the column of liquid. The said liquid constitutes the supply which is employed in the apparatus; when this latter is charged, the column of air in the said branch 1 may be reduced to a simple bubble.

The liquid 12 is heated by means of a plate of the substance designated as meta (solidified alcohol) or of other suitable substance, 0 which is contained in a box 13 whose upper face consists of a grating 14 against which the said plate of substance is held by a spring 15. The device in the said box 13 consisting of the spring may be dispensed with, and thus the plate of 5 meta substance will rest upon a support with fixed bottom, which it entirely fills. The box 13 is mounted on a bottom part 16 which is disposed on the base part of the case 10 in such manner that it will have an inclined position as 50? shown in the drawing, this inclination being less than that of the branch 2 of the said tube, so that the distance between the said plate 20 of solidified alcohol and the tube will diminish towards the bottom, and thus the height of the 5 flame will increase towards the top, as shown in the drawing, whereby the heat will be properly distributed. Due to the inclination of the said box, the plate of substance will burn at the top at a higher rate than at the bottom and consequently the substance be more rapidly consumed at the upper end of said box, and thus the flame will constantly heat the top part of the liquid in the tube and be gradually retracted towards the lower end and thus follow the liquid as it descends, while it also comes nearer the tube.

The case 10 consists preferably of metal, with a removable base 17, and it is provided with orifices for the circulation of air and for the discharge of the products of combustion, and such ventilation also makes the flame more regular. The size and number of such orifices will be so determined as to provide for a reduced rate of combustion of the solidified alcohol. On the top of the case is mounted a knob of nonconducting material 18 serving as a handle to seize the said case.

The operation commences by filling the said tube with a suitable liquid as above indicated, then placing the plate of meta substance in the box 13, the base 17 being separated from the case 10; the substance is lighted, and the said base is inserted in position. Due to'the shape of the flame, the greatest heating takes place near, and also above, the level of the liquid in the branch 2. The apparatus, in operation, acts substantially as a barometric chamber and ensures an automatic regulation of the level of the liquid near the more heated part of the open branch 2. If the level tends to fall below the flame the gas discharge would be nearly stopped 'in the open branch 2, but vapor is however formed in the closed branch 1 which is heated by conduction and the resulting pressure in vertical branch is increased and forces the liquid towards the open branch where the liquid level 5 is substantially maintained. If on the contrary,

the level is too high in the branch 2 and tends to rise above the flame, the gas discharge is considerably increased in said branch and, as vapor can escape only through the small orifice '7, the pressure increases in the open branch 2 and forces the liquid back towards the closed branch 1. Thus the level of liquid tends to remain at the point of the flame as both descend together, because the flame descends during the discharge of vapor and the diminution of the quantity of liquid and this condition is obtained simply by the combustion of the inclined plate 20 of a solid combustible. Such a plate burns 110 at first more in its upper part so that when the upper part has been consumed, the flame descends as indicated and the level of liquid follows the flame due to the discharge of gas and the action of the pressure in the two branches 1 and 2 as explained above.

It may be admitted that when the apparatus is in operation, the vertical part of the tube is entirely emptied of liquid, the space being occupied by a mixture of air and gas which drives the liquid into the heated part of the tube. The valve 5 prevents the pressure in the tube from reaching a dangerous value, as in this event the valve will be lifted against its spring 8, thus opening an annular passage in the. said cap through which the gas Will rapidly issue.

Obviously, the said apparatus is susceptible of various modifications in detail without departing from the spirit of the invention, and for instance the vertical branch of the tube can be closed by a removable device, optionally elastic, which serves as a valve.

' I claim:

1. A medical gas producer using heated liquid having a tube with two branches in communication at the bottom juncture, one branch being vertical and closed at its upper end and containing a column of air and the other branch being inclined and provided with a cap having a narroW orifice, and means for heating the inclined branch at a point gradually descending so as to follow substantially the movement of the level of the liquid.

2. A medical gas producer using heated liquid as claimed in claim 1, a support with a removable bottom for the tube.

3. A medical gas producer using heated liquio as claimed in claim 1, a case forming a support for the tube, the said case having an opening permitting circulation of air and of gases of combustion, the number and the size of the openings being determined so as to limit the speed of combustion.

4. A medical gas producer using heated liquid as claimed in claim 1 having a case forming a support for the tube, a box below the inclined branch of the tube on the bottom of said support, said box being adapted to receive a plate of suitable combustible substance, the box being disposed in such manner that the plate will have an inclined position in the same direction assaid inclined branch of the tube and that its inclination will be less than that of the inclined branch of the tube.

5. A medical gas producer using heated liquid as claimed in claim 1 having a case forming a support for the tube, the bottom of said support carrying a box below the inclined branch of the tube for receiving a plate of suitable combustible substance, the box being disposed in such manner that the plate will have an inclined position and that its inclination will be in the same direction as, but less than, that of the inclined branch of the tube, a lid in the form of a grate covering the box, and a spring contained in said box and adapted to push the plate constantly in the direction of the upper face of the grate.

JEAN NOIROT. 

